CN102646981A - Power system short-circuit current attenuation practical calculation method - Google Patents
Power system short-circuit current attenuation practical calculation method Download PDFInfo
- Publication number
- CN102646981A CN102646981A CN2012101150524A CN201210115052A CN102646981A CN 102646981 A CN102646981 A CN 102646981A CN 2012101150524 A CN2012101150524 A CN 2012101150524A CN 201210115052 A CN201210115052 A CN 201210115052A CN 102646981 A CN102646981 A CN 102646981A
- Authority
- CN
- China
- Prior art keywords
- circuit current
- short circuit
- initial value
- short
- attenuation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention relates to a power system short-circuit current attenuation practical calculation method. The initial value of short-circuit current based on tidal current is taken as the initial value for practical attenuation calculation; under the condition of classical assumption and based on the principle that the flux linkage (electric potential) does not mutate, and taking that the electric potential attenuates along with time into consideration, circuit equations (linear algebraic equations) are listed out and are worked out through a computer to get the attenuation of the short-circuit current. In such way, the initial value of the short-circuit current and the calculation result of attenuation are closer to the practical situation.
Description
Technical field
The present invention relates to a kind of computational methods of short circuit current, particularly a kind of Power System Shortcuts current attenuation practical calculation method.
Background technology
Short circuit is the catastrophe failure of electric power system, and it is extremely important for selecting electric equipment, configuration relaying protection in the electric power system accurately to calculate short circuit current and attenuation thereof.
The conventional method of calculating the short circuit current decay is the calculation of short-circuit current curve method; The restrictions such as generator 's parameter when making curve, load factor, system loading distribution but this method is limited by cause the short circuit current decay error of calculation of practical power systems bigger, and it is too conservative to show as result of calculation; Because specified full-load run before the supposition generator short circuit when making calculated curve; And in practical power systems when operation, considered system safety stability, and most units are not in specified running status.And because network abbreviation problem, calculated curve method also inconvenience is used in actual large power system.
The decay of short circuit current is calculated also can write the electric power system differential equation through row, uses numerical computations to find the solution differential equation group then.Though this method is accurate, amount of calculation is big, is not suitable for carrying out the engineering calculation of short circuit current decay.
For above-mentioned reasons; Electric power enterprise carries out not considering when the Power System Shortcuts electric current calculates the decay of short circuit current at present; Only calculate the initial value of short circuit current; Then other short circuit current constantly after the short circuit is equal to the initial value of short circuit current, makes result of calculation too conservative when reality is used so equally.
Two kinds of short circuit current initial value carculation methods are arranged in the practicality, be divided into based on the short circuit current initial value of trend and calculate and calculate based on the short circuit current initial value of classical assumption.Running status, line parameter circuit value, transformer parameter etc. before the former the electrification system short circuit are accurately considered the load influence of electric power system, it is generally acknowledged the actual state that can fully reflect electrical network, near actual short electric current initial value.The latter ignores that all promptly disregard line charging electric capacity, bus parallel branch and load to the influence of ground leg in the system, and the non-standard no-load voltage ratio of all transformers gets 1.0, and all node voltages are got the average rated voltage (corresponding perunit value is 1) of place electric pressure.The trend distribution influence that this method changes when not normally moved by electric power system at any time, thereby have good practical applications property, but there are certain deviation in the short circuit current initial value and the actual conditions of calculating gained.
Summary of the invention
The present invention be directed to short circuit initial value in the present electric power system and decay and calculate the problem of the deficiency that exists; A kind of Power System Shortcuts current attenuation practical calculation method has been proposed; With the initial value of decaying and calculating as practicality based on the short circuit current initial value of trend; But under the classical assumption condition,, consider that electromotive force is along with the time decays, through row write circuit equation (linear algebraic equation group) based on magnetic linkage (electromotive force) principle of not suddenling change; Obtain the attenuation of short circuit current with computer solving, thereby make the initial value of short circuit current and the result of calculation that decays all more near actual conditions.
Technical scheme of the present invention is: a kind of Power System Shortcuts current attenuation practical calculation method comprises following concrete steps:
1) under the situation that known trend distributes, the short circuit current initial value being carried out in preset fault point calculates; Obtain short circuit current initial value result, be designated as
based on trend;
2) adopt the classical assumption condition to form node admittance matrix, the particular content of classical assumption is following:
A: adopt average rated voltage as voltage reference, ignore the rated voltage of each element and the difference of the average rated voltage of relevant voltage grade;
B: ignore that all promptly disregard line charging electric capacity, static exciter branch road, bus parallel branch and load to the influence of ground leg in the system;
C: think that transformer voltage ratio equals the ratio of the average rated voltage of side, promptly the mark of all transformers one no-load voltage ratio equals 1.0;
3) to preset fault point, according to the decay calculating that electromotive force does not suddenly change and carries out the generator electromotive force, be example with generator d axle, computing formula is following:
In the formula,
is moment d axle time transient potential before the generator short circuit;
is moment stator winding d shaft current before the generator short circuit;
is respectively steady-state reactance, transient state reactance and the subtranient reactance of generator;
be after the short circuit of calculating based on the node admittance matrix of classical assumption moment generator terminal voltage and the merchant of machine end electric current;
is respectively transient state component and time time constant of transient state component decay;
4) separate network equation; Obtain after the short circuit each attenuation of periodic component of short-circuit current constantly according to the decay of generator electromotive force, be designated as
(
);
5) calculate gained each constantly value
based on short circuit current initial value result
the correction step 4) of trend based on the periodic component of short-circuit current decay of classical assumption with step 1), correction formula is following:
In
formula,
is based on trend and deviation based on the short circuit current initial value of classical assumption;
is the short circuit current initial value result based on classical assumption;
is each revised short circuit current attenuation results constantly; The short circuit current attenuation curve that correction formula is equivalent to step 4) is obtained carries out translation; Initial value is consistent with short circuit current initial value result based on trend before making, thereby obtains revised short circuit current attenuation curve.
Beneficial effect of the present invention is: Power System Shortcuts current attenuation practical calculation method of the present invention, Power System Shortcuts current attenuation practical calculation method makes the initial value of short circuit current and the result of calculation that decays all more near actual conditions.Use method result of calculation of the present invention to have higher accuracy, the goodness of fit of short circuit current attenuation curve and electromechanical transient is also better, and result calculated has certain margin of safety generally greater than the result of electromechanical transient.
Description of drawings
Fig. 1 is the network configuration and the preceding trend distribution map of short circuit of Power System Shortcuts current attenuation practical calculation method instance of the present invention one IEEE9 system;
Fig. 2 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance one bus BusA three-phase shortcircuit of the present invention;
Fig. 3 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance one bus Bus1 three-phase shortcircuit of the present invention;
Fig. 4 is the network structure of Power System Shortcuts current attenuation practical calculation method instance of the present invention two IEEE39 systems;
Fig. 5 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance two buses 8 three-phase shortcircuits of the present invention;
Fig. 6 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance two buses 13 three-phase shortcircuits of the present invention;
Fig. 7 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance two buses 16 three-phase shortcircuits of the present invention;
Fig. 8 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance two buses 20 three-phase shortcircuits of the present invention;
Fig. 9 is periodic component of short-circuit current decay sketch map during for Power System Shortcuts current attenuation practical calculation method instance two buses 39 three-phase shortcircuits of the present invention.
Embodiment
The practical implementation step of the practical calculating of short circuit current decay new method is following:
(1) under the situation that known trend distributes, the short circuit current initial value being carried out in preset fault point calculates; Obtain short circuit current initial value result, be designated as
based on trend.
(2) adopt the classical assumption condition to form node admittance matrix, the particular content of classical assumption is following:
A: adopt average rated voltage as voltage reference, ignore the rated voltage of each element and the difference of the average rated voltage of relevant voltage grade;
B: ignore that all promptly disregard line charging electric capacity, static exciter branch road, bus parallel branch and load to the influence of ground leg in the system;
C: think that transformer voltage ratio equals the ratio of the average rated voltage of side, promptly the mark of all transformers one no-load voltage ratio equals 1.0.
(3) to preset fault point, according to the decay calculating that electromotive force does not suddenly change and carries out the generator electromotive force, be example with generator d axle, computing formula is following:
In the formula,
is moment d axle time transient potential before the generator short circuit;
is moment stator winding d shaft current before the generator short circuit;
is respectively steady-state reactance, transient state reactance and the subtranient reactance of generator;
be after the short circuit of calculating based on the node admittance matrix of classical assumption moment generator terminal voltage and the merchant of machine end electric current;
is respectively transient state component and time time constant of transient state component decay.
(4) separate network equation; Obtain after the short circuit each attenuation of periodic component of short-circuit current constantly according to the decay of generator electromotive force, be designated as
(
).
(5) calculate gained each constantly value
based on short circuit current initial value result
the correction step (4) of trend based on the periodic component of short-circuit current decay of classical assumption with step (1), correction formula is following:
?(2)
In the formula,
is based on trend and deviation based on the short circuit current initial value of classical assumption;
is the short circuit current initial value result based on classical assumption;
is each revised short circuit current attenuation results constantly.Formula (2) is equivalent to the short circuit current attenuation curve that step (4) obtains is carried out translation, and initial value is consistent with short circuit current initial value result based on trend before making, thereby obtains revised short circuit current attenuation curve.
Practicality calculating new method and other computational methods that the present invention is proposed compare, the existing regulation as follows: traditional utilization calculated curve is calculated the method for short circuit current decay, be called the calculated curve method; To obtain short circuit current calculation of attenuation method through finding the solution the differential equation, be called electromechanical transient.
Here select IEEE9 system and IEEE39 system respectively as applicating example of the present invention.Consider that the calculating of electromechanical transient adopts the differential equation without algebraic simplification, accurately considered the quasi steady state model of generator, result of calculation is near actual conditions, the present invention with the result of calculation of electromechanical transient as standard of comparison.
Instance one: the practicality that proposes according to the present invention is calculated new method the bus BusA of IEEE9 system is carried out short circuit current decay calculating with bus Bus1, and the result of calculation that lists file names with the calculated curve method as a comparison.Trend distributes before the network configuration of IEEE9 as shown in Figure 1 system and the short circuit, during result of calculation bus BusA as shown in table 1 three-phase shortcircuit during bus Bus1 three-phase shortcircuit shown in periodic component of short-circuit current decay result of calculation, the table 2 when periodic component of short-circuit current decay result of calculation and Fig. 2 bus BusA three-phase shortcircuit when periodic component of short-circuit current decay sketch map, Fig. 3 bus Bus1 three-phase shortcircuit shown in the periodic component of short-circuit current decay sketch map.
Table 1
Table 2
Can find out that from table 1, table 2 and Fig. 1, Fig. 2 the result of calculation of practical calculating new method and electromechanical transient is very approaching, the phase rate is all in ± 1%.When bus BusA was short-circuited, the maximal phase rate was 0.63% (0.1s after short circuit); When bus Bus1 was short-circuited, the maximal phase rate was-0.90% (0.08s after short circuit).
By contrast, the result of calculated curve method is too conservative.If short circuit occurs in bus BusA, all in 10%, the maximal phase rate is 7.51% (0.09s after short circuit) to the phase rate; If short circuit occurs in bus Bus1, the phase rate is all greater than 10%, and the maximal phase rate is 14.87% (0.02s after short circuit).
And the result of calculation of the practicality that the present invention proposes calculating new method has higher accuracy, and the goodness of fit of short circuit current attenuation curve and electromechanical transient is also better.
Instance two: the network configuration of IEEE39 as shown in Figure 4 system; The short circuit current decay that proposes according to the present invention is practical calculates new method and bus 8, bus 13, bus 16, bus 20 and the bus 39 of IEEE39 system carried out the short circuit current decay calculates; Consider that the calculated curve method need be to the artificial conversion of network; Not only workload is big, and has seen in conservative from the effect of applicating example 1, so the IEEE39 system no longer adopts the calculated curve method to calculate.Periodic component of short-circuit current decay result of calculation during result of calculation bus 8 three-phase shortcircuits as shown in table 3; Periodic component of short-circuit current decay sketch map during Fig. 5 bus 8 three-phase shortcircuits; Periodic component of short-circuit current decay sketch map during Fig. 6 bus 13 three-phase shortcircuits; Periodic component of short-circuit current decay sketch map during Fig. 7 bus 16 three-phase shortcircuits; Periodic component of short-circuit current decay sketch map during Fig. 8 bus 20 three-phase shortcircuits; Periodic component of short-circuit current is decayed shown in the sketch map during Fig. 9 bus 39 three-phase shortcircuits.
Table 3
Can find out from table 3, Fig. 5 to Fig. 9; The practical new method of calculating of short circuit current decay is compared with the result of calculation of electromechanical transient; Still comparatively conservative; In 5 short dots of stochastic calculation, maximum positive rate is 10.32% (0.1s after bus 20 short circuits), and maximum negative phase rate is-1.14% (0.1s after bus 39 short circuits); And except that bus 39, the phase rate of all the other short dot result of calculations is all greater than zero, and the promptly practical result who calculates new method has certain margin of safety generally greater than the result of electromechanical transient.
Claims (1)
1. a Power System Shortcuts current attenuation practical calculation method is characterized in that, comprises following concrete steps:
1) under the situation that known trend distributes, the short circuit current initial value being carried out in preset fault point calculates; Obtain short circuit current initial value result, be designated as
based on trend;
2) adopt the classical assumption condition to form node admittance matrix, the particular content of classical assumption is following:
A: adopt average rated voltage as voltage reference, ignore the rated voltage of each element and the difference of the average rated voltage of relevant voltage grade;
B: ignore that all promptly disregard line charging electric capacity, static exciter branch road, bus parallel branch and load to the influence of ground leg in the system;
C: think that transformer voltage ratio equals the ratio of the average rated voltage of side, promptly the mark of all transformers one no-load voltage ratio equals 1.0;
3) to preset fault point, according to the decay calculating that electromotive force does not suddenly change and carries out the generator electromotive force, be example with generator d axle, computing formula is following:
In the formula,
is moment d axle time transient potential before the generator short circuit;
is moment stator winding d shaft current before the generator short circuit;
is respectively steady-state reactance, transient state reactance and the subtranient reactance of generator;
be after the short circuit of calculating based on the node admittance matrix of classical assumption moment generator terminal voltage and the merchant of machine end electric current;
is respectively transient state component and time time constant of transient state component decay;
4) separate network equation; Obtain after the short circuit each attenuation of periodic component of short-circuit current constantly according to the decay of generator electromotive force, be designated as
(
);
5) calculate gained each constantly value
based on short circuit current initial value result
the correction step 4) of trend based on the periodic component of short-circuit current decay of classical assumption with step 1), correction formula is following:
In
formula,
is based on trend and deviation based on the short circuit current initial value of classical assumption;
is the short circuit current initial value result based on classical assumption;
is each revised short circuit current attenuation results constantly; The short circuit current attenuation curve that correction formula is equivalent to step 4) is obtained carries out translation; Initial value is consistent with short circuit current initial value result based on trend before making, thereby obtains revised short circuit current attenuation curve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012101150524A CN102646981A (en) | 2012-04-19 | 2012-04-19 | Power system short-circuit current attenuation practical calculation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012101150524A CN102646981A (en) | 2012-04-19 | 2012-04-19 | Power system short-circuit current attenuation practical calculation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102646981A true CN102646981A (en) | 2012-08-22 |
Family
ID=46659632
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012101150524A Pending CN102646981A (en) | 2012-04-19 | 2012-04-19 | Power system short-circuit current attenuation practical calculation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102646981A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102944720A (en) * | 2012-11-21 | 2013-02-27 | 上海电力学院 | Short-circuit current attenuation calculating method with consideration of dynamic load for power system |
| CN106410783A (en) * | 2016-04-14 | 2017-02-15 | 上海电力学院 | Power system short circuit current attenuation calculating method based on coordinate transformation |
| CN113447803A (en) * | 2021-06-08 | 2021-09-28 | 国网上海市电力公司 | Short-circuit current calculation voltage coefficient value taking method for checking on-off capacity of circuit breaker |
-
2012
- 2012-04-19 CN CN2012101150524A patent/CN102646981A/en active Pending
Non-Patent Citations (3)
| Title |
|---|
| 丁北平: "基于PSS/EBKDY模块的短路电流周期分量计算方法分析", 《上海电力学院学报》 * |
| 吕文杰: "三相短路电流计算方法的探讨", 《四川电力技术》 * |
| 曹炜等: "PSS/E BKDY 短路计算模块评述", 《华东电力》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102944720A (en) * | 2012-11-21 | 2013-02-27 | 上海电力学院 | Short-circuit current attenuation calculating method with consideration of dynamic load for power system |
| CN102944720B (en) * | 2012-11-21 | 2015-02-25 | 上海电力学院 | Short-circuit current attenuation calculating method with consideration of dynamic load for power system |
| CN106410783A (en) * | 2016-04-14 | 2017-02-15 | 上海电力学院 | Power system short circuit current attenuation calculating method based on coordinate transformation |
| CN106410783B (en) * | 2016-04-14 | 2019-02-22 | 上海电力学院 | A kind of Power System Shortcuts current attenuation calculation method based on coordinate transform |
| CN113447803A (en) * | 2021-06-08 | 2021-09-28 | 国网上海市电力公司 | Short-circuit current calculation voltage coefficient value taking method for checking on-off capacity of circuit breaker |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kawabe et al. | Analytical method for short-term voltage stability using the stability boundary in the PV plane | |
| Kamel et al. | A novel hybrid ant colony-particle swarm optimization techniques based tuning STATCOM for grid code compliance | |
| CN103199526B (en) | Short circuit power frequency electrical quantity calculating method for power system comprising doubly-fed induction generator | |
| CN102938563B (en) | A kind of electric railway electric energy quality comprehensive treatment device | |
| CN102403716A (en) | Dynamic equalizing method for multi-infeed alternating/direct-current power grid | |
| CN102882208B (en) | A kind of electric railway electric energy quality comprehensive treatment device control method | |
| WO2019007354A1 (en) | Short-circuit current calculation method for doubly-fed wind power generation system considering different slips | |
| CN106066918A (en) | Based on homotopy containing distributed power source and the short-circuit current calculation method of nonlinear-load | |
| Bidram et al. | Capacitor design considering first swing stability of distributed generations | |
| CN102361329A (en) | Modeling method for performing dynamic characteristic research on hybrid alternating current/direct current (AC/DC) transmission system | |
| Ahmad et al. | A placement method of fuzzy based unified power flow controller to enhance voltage stability margin | |
| CN104079010A (en) | Transient stability emergency control strategy calculating method with generator tripping and direct-current emergency power modulation coordinated | |
| CN103217623B (en) | The line double-end fault distance-finding method had nothing to do with transition resistance and load current | |
| CN102646981A (en) | Power system short-circuit current attenuation practical calculation method | |
| CN116247726A (en) | Method and system for calculating accessible capacity and evaluating bearing capacity of distribution network system | |
| Juanuwattanakul et al. | Voltage stability enhancement for unbalanced multiphase distribution networks | |
| CN103543315A (en) | Impedance network analysis method of short-circuit current of 500 kV autotransformer | |
| CN106981880B (en) | Quantitative calculation method for unbalanced responsibility at public coupling point in power distribution system | |
| Peters et al. | Static VAR compensation of a fixed speed stall control wind turbine during start-up | |
| CN106410783A (en) | Power system short circuit current attenuation calculating method based on coordinate transformation | |
| CN105262046B (en) | Relay protection fixed value setting method based on electromechanical transient method | |
| CN104899677B (en) | The radial supply network load maximum reactive requirements of 500kV estimate method soon during disturbance restores | |
| CN102495262B (en) | Improved calculation method for classical assumption of short-circuit current | |
| Mobarak et al. | Voltage Instability of Initiation Fault Duration as Influenced by Nodes Short Circuit Levels NSCL. | |
| CN205753432U (en) | Three-phase load unbalance self-checking device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120822 |